Flat Panel Display (FPD) devices are widely used due to the advantages of being compact and portable. A main technology for future FPDs is Organic Light Emitting Diode (OLED) display technology. In comparison with Liquid Crystal Display (LCD) technology operated in an overall backlight mode, OLED displays works in a self-luminant mode such that all the pixels in the OLED can emit light. As a result, the OLED displays can notably increase view angles and contrast while reducing power consumption and thickness.
Touch screens as a modern way of inputting has been used as a main input device in various portable electronic products and are gradually replacing conventional mechanical keypad input device. It is expected that an all-touch non-keypad input mode will be eventually realized in such electronic products. The touch screen technology has undergone various development stages, which mainly includes resistive touch screens, capacitive touch screens, optical sensing touch screens, and electromagnetic sensing touch screens. Currently the mainstream touch screens are the resistive touch screens; however, capacitive touch screens are rapidly catching up. The capacitive touch screens generally include self-capacitance touch screens, surface capacitance touch screen, projected capacitance touch screens and so on.
On the other hand, conventional touch screens made of OLEDs are mostly add-on capacitive touch screens, which have the disadvantages of having high cost, low touch sensitivity and low reliability.